1. Field of the Invention
This invention relates generally to the separation of solid particles that are entrained in gas from the entrainment gas and, more particularly, relates to the separation of the components of a gaseous stream which include wood fibers entrained in steam so as to obtain at separate stations the fibers free of steam and at another station the steam free of fibers.
2. Prior Art
In the manufacture of paper and the like, wood chips are subjected to a chemical action or to a combination of mechanical and chemical action and reduced to fine fibers. Conventionally, these fibers are then conveyed to a further processing station through a pipe at a velocity of between 5,000 and 30,000 feet per minute by means of steam.
When the entrained fibers arrive at the process station, it has been conventional to pass the entrainment of steam and fibers through a cyclone separator which separates the fibers from the steam. In such separators, the entrainment enters at the top tangentially and starts spinning downwardly of its own force. The centrifugal force separates the heavier fibers from the steam. The fibers leave at the bottom and the steam leaves at the top of the separator. Cyclone separators perform quite effectively until a layer of stationary fibers build up on the interior walls of the separator. When the weight of the stationary material on the wall is heavy enough to overcome the force of adhesion, the layer of material drops downwardly toward the bottom outlet of the separator. This falling layer of material can be so large and so thick as to block the discharge outlet of the separator. Even if the discharge outlet is not fully blocked, the erratic discharge of the material can adversely affect the performance of subsequent processing operations conducted on the material.